Wetland seasonal dynamics and interannual variability over northern high latitudes, derived from microwave satellite data

• Published in: Journal of Geophysical Research
• Main Authors: Mialon, Arnaud, Royer, A., Fily, Michel
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'Applications et de Recherches en TELédétection Sherbrooke (CARTEL), Département de géomatique appliquée Sherbrooke (UdeS), Université de Sherbrooke (UdeS)-Université de Sherbrooke (UdeS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Canada; ob river; Alaska
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00374874; https://hal-insu.archives-ouvertes.fr/insu-00374874/document; https://hal-insu.archives-ouvertes.fr/insu-00374874/file/2004JD005697.pdf; https://doi.org/10.1029/2004JD005697

International audience A new accurate determination of the spatial and temporal variations of northern wetland area extent, during the snow-free period, is retrieved from the 19- and 37-GHz passive microwave Special Sensor Microwave/Imager (SSM/I) brightness temperature database. The total fraction of water surface (FWS) area, corresponding to small lakes or reservoirs (area < 25 × 25 km2), inundated surfaces and natural wetland areas, computed on a weekly basis and averaged over the 1988–2001 period, gives a maximum summer extent of 10.10 ± 0.21 × 105 km2 for Canada and Alaska and 12.7 ± 0.35 × 105 km2 for Eurasia, above 50°N. The mean seasonal dynamics of wetland and inundated surfaces shows a maximum area extent during the months of July-August-September over North America (48°N–68°N) and between June and September over northern Eurasia. The interannual variations of the yearly total FWS area since 1988 show a slight increase (8% ± 3%) in Canada-Alaska, mainly due to a decrease in the snow cover extent. The FWS interannual variability in the Ob River basin, which is well explained by the water discharge variations, shows an increase of 8.5% ± 1.5% between 1988 and 2001. The microwave-derived FWS estimate and its dynamics present an interesting potential for studying the climate-driven variability of wetlands and inundated areas.